Here is the ultimate guide to writing RPG IV programs with functions in the free-format style. Let RPG expert and best-selling author Jim Martin show you the way. Want to generate a random number, manipulate a character string, or determine the number of elements in a data structure? There's a function for that. Jim will even show you how to write your own custom built-in functions (BIFs).

In this book, you'll discover the role of functions in free-format RPG IV. Jim explains the details of built-in functions (BIFs) and explores the use of C language functions, do-it-yourself functions (subprocedures), and prototyping and
procedure interfaces for function connectivity of RPG IV main procedures with subprocedures and other modules. Because functions rely heavily on ILE, the book examines those ILE concepts that connect the parts of a multi-functional program, such as binding, import/export of data, service programs, and binding directories. In addition, you'll find how to prototype IBM's APIs.

Modular programming is important, and it's powerful. Programmers need to understand modular concepts in depth, including all the interfacing tools needed to make programs perform well. Inside this book, you'll find everything a free-format RPG IV programmer needs to know about using existing RPG IV BIFs, writing new functions, leveraging ILE concepts to use C functions, and using IBM APIs as functions.

Understand ILE concepts such as binding by copy, binding by reference, import/export of data, service programs, signatures, and binding directories

Learn how to analyze needs for a new program, with respect to modularization and functions

About author

Jim Martin —Jim Martin holds a BS degree in mathematics and an MS in computer science. For 26 years, he was employed by IBM, where he wrote RPG applications for customers and worked in the programming laboratory as a programmer on portions of CPF and the OS/400 operating system. After leaving IBM, Jim took post-graduate work in computer science and performed RPG training. He is an IBM-certified RPG IV developer and author of the bestselling first and second editions of Free-Format RPG IV, which, since the book's initial publication in 2005, have taught thousands of RPG IV programmers how to be successful with the free-format coding style.